In electronic parts packaging machines which have heretofore been employed, a variety of electronic parts have to be tested for lead misalignment and then mounted in such a manner as to ensure high quality.
An example of a conventional electronic parts mounting machine will now be described with reference to FIG. 5.
In FIG. 5, the numeral 1 denotes a circuit board on which an electronic part 10 is to be mounted, and 2 denotes a pair of rails for carrying in and out the circuit board 1. The numeral 3 denotes parts feeding sections each comprising feeding means disposed in parallel, said parts feeding sections being fixedly disposed on opposite sides of the rails 2. The numeral 4 denotes a mounting head having a suction nozzle 5 for sucking the electronic part 10 and is vertically movable. This mounting head 4 is driven for positioning by an XY robot 6 in two directions, X-direction and Y-direction, which are orthogonal to each other in a horizontal plane.
Further, the electronic parts mounting machine is equipped with a recognition camera 7 for photographing the electronic part 10 sucked by the suction nozzle 5. The position at which the electronic part 10 is sucked by the suction nozzle 5 is measured by this recognition camera 7, it being arranged so that the latter takes in the image data for calculating the positional corrected amount to be later described. The numeral 8 denotes a lead misalignment tester for testing lead-equipped electronic parts for the misaligned state of their leads by a laser beam. The numeral 9 denotes a controller for the entire electronic parts mounting machine.
The operation of this electronic parts mounting machine will now be described. The circuit board 1 is carried in by the rails 2 and positioned and held at a predetermined electronic parts mounting position. The mounting head 4 is moved by the XY robot 6 to the parts feeding section 3 where electronic parts 10 have been stored, whereupon the mounting head 4 equipped with the suction nozzle 5 is lowered to suck an electronic part 10.
The mounting head 4 with the electronic part 10 sucked thereby is moved to a place above the recognition camera 7 and positioned there. The recognition camera 7 takes in the image of the electronic part 10 sucked by the section nozzle 5 and measures the position of the electronic part 10 to find the positional corrected amount. Upon completion of this positional correction, the electronic part 10 is moved by the mounting head 4 to the test position in the laser lead misalignment tester 8. The XY robot 6 is driven in the X- and Y-directions in such a manner that all leads on the individual sides of the electronic part 10 block the test laser irradiating spot (scan spot) of the lead misalignment tester 8, while the mounting nozzle 5 is rotated. Thereafter, only those electronic parts 10 which have been found normal by the lead misalignment test results are mounted on the circuit board 1. The circuit board 1 having undergone the mounting operation is carried out by the rails 2. The sequence described above is controlled by the controller 9.
With such electronic parts mounting machine of a conventional arrangement, however, lead misalignment tests are conducted by driving the XY robot 6 in the X- or Y-direction such that the individual leads of the electronic part 10 are moved with respect to the scan spot on the lead misalignment tester. For this reason, if the electronic parts mounting machine does not have means, such as the XY robot 6, for driving in two orthogonal directions, then it is impossible to conduct lead misalignment tests in the case of an electronic parts mounting machine of the rotary head type adapted to mount parts while rotating a plurality of heads 4.
As an approach to this difficulty, it would be contemplated to conduct lead misalignment tests by moving the test unit of the lead misalignment tester 8 in the X- and Y-directions with the electronic part 10 sucked by the mounting nozzle 5 and fixed in a predetermined position. In this case, the test unit of the lead misalignment tester 8 has to move in two different directions, i.e., X- and Y-directions, and hence errors in movement would be correspondingly increased, leading to a lowering of measurement accuracy, while a larger space has to be allocated for the installation and movement of the test unit of the lead misalignment tester 8.